# awk script 
# written by Dave Leo, Nov.2007
# external forced convection coefficients on pipe outside wall
#
# the begin command is executed BEFORE anything else is done
BEGIN {FS=" ";
"date" | getline date;
print date
}
# Read input data from file.................................
#
{N=N+1}
{if(N==1) {printf "Input file [ %12s ]\n",FILENAME ;
print "#----------------------Input---------------------#"}}
{if($1=="Diameter") {diam=$2;print$0}}
{if($1=="Velocity") {vel=$2;print$0}}
{if($1=="Rgas") {rgas=$2;print$0}}
{if($1=="kgas") {kgas=$2;print$0}}
{if($1=="Cpgas") {cpgas=$2*1000.;print$0}}
{if($1=="mugas") {mugas=$2;print$0}}
{if($1=="Tgas") {tgas=$2;print$0}}
{if($1=="Pgas") {pgas=$2;print$0}}
#
# Do calculations ..........................................
#
END {
# input dimension are mm's 
{gasdens=pgas/rgas/(tgas+273.15)}
{prndlt=cpgas*mugas/kgas}
# (note: diam in input in mm's, velocity is m/s)
{rend=gasdens*vel*diam/mugas/1000.}
{scratch1=.62*sqrt(rend)*(prndlt^.333)}
{scratch2=(1.+(.4/prndlt)^.67)^.25}
{scratch3=(1+(rend/282000.)^.625)^.80}
{Nud=0.3+scratch1*scratch3/scratch2}
{hext=Nud*kgas*1000/diam}
#
{print" "}
#
# Print output data to file .................................
#
{print "#----------------------Output--------------------#"}
{printf("%-12s %12.3f\n","Fluid Density", gasdens)}
{printf("%-12s %12.3f\n","Prandlt No.",prndlt)}
{printf("%-12s %12.0f\n","Reyn(D)",rend)}
{printf("%-12s %12.1f\n","Nu(D)",Nud)}
{printf("%-12s %12.1f\n","Haverage",hext)}
#
{print "#.......................End of File..............#"}
}